Cosmos

Value to bees

Nectar

High

Pollen

High

As a honey crop

Feeds the colony but rarely yields a surplus

Which bees, and why

The open disc is a landing platform with completely exposed nectar and pollen, which makes it usable by essentially every flower-visiting insect — including small solitary bees and hoverflies that cannot feed from tubular flowers at all.

Nothing is hidden. This is the most accessible flower architecture there is, and the reason single open-faced flowers matter so much in a bee garden.

Worth knowing

Good ratings for both, delivered over months, from a plant that costs almost nothing. Its efficiency per pound spent is hard to beat.

Flowering

In flower

July to October (northern hemisphere)

Flowers continuously if deadheaded, right up to the first frost. Sowing in succession in April and June extends it further.

When nectar flows

Nectar and pollen are both freely available on the open central disc. Each 'flower' is many small fertile florets, so a single head keeps an insect working for some time.

Year-to-year variation

Reliable in any warm sunny summer. Not a honey crop.

Growing it

Conditions

Full sun, poor to moderate soil. Rich soil and feeding produce enormous foliage and few flowers, which is worth knowing before improving the ground for it.

Size

60-150 cm.

Native range

Mexico and the southern United States.

Suits

Containers and window boxes, Small gardens, Large gardens, Meadow or wildflower area

• Buy single-flowered varieties. Double and semi-double cosmos have had the fertile disc florets converted into petals and offer a fraction of the forage — this is the clearest example in a seed catalogue of the single-versus-double rule.
• Sow direct after the last frost, or start indoors in April. It is one of the easiest annuals from seed.
• Deadhead regularly and it will flower until frost; stop, and it sets seed and stops.
• Do not feed it. Poor soil produces more flowers.

What it looks like

A tall airy annual with finely dissected feathery foliage and large daisy flowers in white, pink or magenta, with a broad yellow disc of tiny fertile florets at the centre.